In-place aerobic exercising has become the exercise of choice for many in recent years. Step aerobics, which involves the use of a raised step or small platform, has enjoyed wide popularity in particular. In a step aerobic routine, one repeatedly steps up and down between the floor and the raised platform and/or performs a series of maneuvers on the platform designed to fully exert the cardiovascular system.
The raised platform most often used in step aerobics is typically supported by a sturdy, low-profile base unit formed of high impact plastic or other strong, lightweight material with rounded edges. The platform is typically integrally formed with the base and thus is made of the same high impact material. The entire unit is thus safe, durable, inexpensive, compact, and easy to carry or stow away, which may be at least part of the reason for the popularity of step aerobics.
Risers of one kind or another can typically be removably attached to the bottom of the base unit. When so attached, the risers raise the level of the platform above the floor, thus requiring the user to exert more aerobic effort. As a user becomes more proficient at a given exercise routine, risers of increasingly larger size may be used with the same basic step unit, to permit the user to select the level of effort appropriate for him or her.
One drawback of step aerobics is that repeated stepping up and down on the platform results in repeated impacts upon the ankles, feet, knees, hips, and leg and foot muscles. These repetitious impacts can eventually produce undesirable excessive stress on the muscles and even bone structure, as well as irritation to nerves.
It is known to provide trampoline devices for jump exercising, which are attractive because of their highly resilient surfaces which provide rebound force while reducing abnormal stresses to the body. Examples of such trampolines are found in U.S. Pat. Nos. 3,767,009, 3,767,192, 4,119,311 and 4,381,861. Trampolines usually comprise a perimeter frame which is supported above the floor by legs. Positioned within the frame is a mat which is connected around its perimeter to the frame by springs so that the mat is resiliently supported by the flames.
At first glance, one might think it would be easy to combine the qualities of a step exerciser with those of a trampoline. In actuality, however, that has not proven to be the case. Although there are scaled-down versions of trampolines that may be used in the home and in other places where ceiling heights are limited, none of these scaled down trampolines has to date been successfully adapted to step aerobics.
One reason is that such trampoline devices utilize springs to support the jumping surface. Such springs typically provide too much resilience, that is, their rebounding action is typically much greater than that which is normally considered suitable for step aerobics.
Another reason is that trampolines, in order to remain stabile, must have a relatively high profile above the floor. This requires the user to jump much higher than is normally considered appropriate for step aerobics.
The presence of springs, typically disposed around the perimeter of the mat, also represent a hazard of sorts for stepping. The springs themselves are not particularly resilient, and when one attempts to perform the repeated stepping on and off of the platform required in normal step aerobic routines, invariably the springs end up being stepped upon rather than the mat. This not only upsets the exercise pattern, but may also lead to injury.
Conventional trampolines, even the scaled down ones, also tend to be relatively complicated and expensive devices, and require many heavy metal parts as well as the multitude of springs to reliably support the trampoline mat. Because of the weight of these springs metal pans and the aforementioned high profile and large foot print, trampolines are more difficult to transport and stow away than standard step aerobic devices.